I have to design by myself a capacitive level sensor. To create my "capacitor", I use two copper strips that I take from a copper tape and put it on the tank where I have to take the measurement.
However, the measurement must be a voltage or a current as my PID controller can only "read" this kind of value. Therefore, it means that I need something to change my measured capacitance into a V/I and I do not find an easy way to achieve the conversion. By easy way, I mean that I am in a city where there are not a lot of electronic devices that are available so easy means "without too many components hard to find".
The specifications of my system are the following ones:
Measured Capacitance : [5pF(low level) --> 35pF(High level)]
This is the full range but I could use a small range inside this one
Input of Controller: 0-10V or 4-20mA
I hope that someone can resolve my problem, or at least give me an idea. Thank you in advance.